Leg swelling can occur in any part of the legs, including the feet, ankles, calves and thighs. Leg swelling can result either from fluid buildup (fluid retention) or from inflammation in injured or diseased tissues or joints.

Many of the causes of leg swelling, such as an injury or prolonged standing or sitting, are easily identified. Sometimes leg swelling may be a sign of a more serious disorder, such as heart disease or a blood clot.

Seek medical care right away when leg swelling occurs for no apparent reason or you also have difficulty breathing, chest pain or other warning signs of a blood clot in your lungs or a serious heart condition.

Seek emergency medical care if you have leg swelling and any of the following signs or symptoms, which may indicate a blood clot in your lungs or a serious heart condition:

Chest pain lasting more than a few minutes

Difficulty breathing

Fainting or dizziness

Confusion

Also, seek immediate care if your leg swelling:

Occurs for no apparent reason

Is related to a physical injury, such as from a fall, a sports injury or a car accident

Schedule a doctor's visit

Nonemergency problems related to leg swelling still need prompt care. Leg swelling that is the side effect of a drug can look just like leg swelling caused by a kidney disorder. Make an appointment as soon as possible so that your doctor can diagnose the underlying problem.

Before your appointment, consider the following tips:

Put a pillow under your legs when lying down, which may lessen swelling related to the buildup of fluid.

If you need to stand or sit for long periods, give yourself frequent breaks and move around, unless the movement causes pain.

Don't stop taking a prescription medication without talking to your doctor, even if you suspect it may be causing leg swelling.

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